The rapid evolution of communication networks, including wireless communication networks for mobile communications such as Global System for Mobile communications (GSM) networks, 3G networks, etc., has substantially increased the load on existing network infrastructures of cellular operators. Along with the evolution of communication technologies, a common communication session has also evolved in complexity and is often comprised of several data (media) types such as voice, video, computer data, signaling, etc. Additionally, a single connection between two points representing a source and a destination of a communication session may be conducted over a combination of several network types including PSTN, TDMA, FDMA, ATM, IP, CDMA, cellular networks (1G or 2G or 3G or, eventually, 4G), microwave links, etc. Moreover, a certain class of data being transferred within a given communication session may further be compressed and/or encrypted.
The topologies associated with today's mobile communications networks vary. A common network topology having a central location and a plurality of users can be depicted as having the shape of a tree. In such a tree-like architecture, a central point may be connected to one or more intermediate nodes with each intermediate node having connections to one or more other intermediate nodes and/or to one or more end-user devices (terminals). For example, in a 3G network a central node may be a Radio Network Controller (RNC) and an intermediate node may be a node base station (Nb). Another common mobile telecommunications network topology can be illustrated by the shape of a ring in which a central point (RNC for example) and an intermediate node (Nb, for example) are connected to the ring. Regardless of the specific topology of a mobile telecommunications network, an RNC is commonly used in the role of a central node whereas an Nb most commonly performs as an intermediate node. Accordingly, it should be understood that the description, drawings and claims of the present application may use the term “RNC” as a representative term for a central node and the term “Nb” as a representative term for an intermediate node. Further, exemplary mobile terminals (MT) referenced in this application can be a cellular phone, a PDA with cellular capabilities, or any other computerized device capable of generating and/or receiving any combination of audio, video, or data via a communication network such as, but not limited to, a cellular network.
In a mobile telecommunications network, an RNC is commonly used as an aggregation point for different data types being transferred to and from a plurality of MTs. An RNC is operable to receive circuit switched telephony traffic as well as packet switched traffic traveling to and from the Internet, for example. Further, it is common for a communication line between a central point and an intermediate node to carry a plurality of communication sessions, each having different media types, between one or more other intermediate nodes and/or one or more terminals. Different types of networks and protocols can be employed over a typical communication line. A communication line can be based on Time Division Multiplexing Access (TDMA), Asynchronous Transfer Mode (ATM), Ethernet, etc. and each communication line may be divided into a plurality of channels with each channel being dedicated to a single connection between two terminals.
With some communication protocols, a given channel may be divided into two or more sub-channels. Each sub-channel may be subsequently dedicated to a single connection (session). Usually, the data transportation over a connection between an intermediate node and a central node is organized in layers such as a user layer, an adaptation layer and a data link layer. An exemplary user's layer may comprise the application layer, presentation layer, session transport layer and the network layer of the Open Systems Interconnection Model (OSI). An exemplary adaptation layer may be of an ATM Adaptation Layer type (AAL-2) while an exemplary data link layer may be ATM. In each layer the data can be organized in data units such as frames, packets, chunks, sub-frames, etc. and it should be noted that the terms “frames,” “packets,” “chunks,” and “sub-frames” may be used interchangeably herein. Further, each frame may have a header and a payload. For example, data of a 3 G communication over an ATM bearer may be encrypted, divided into small ATM cells, and aggregated with a portion of data that is associated with other communication sessions between other users.
Clearly, the overall network topology for modern mobile telecommunications networks can be very complex. The result of such complexity is that a single communication connection between two intermediate nodes over a fixed network, or backbone, of a cellular operator may be comprised of a combination of network standards, communication protocols, compression standards, and encryption methods for a plurality of users.
In a 3G network, a user layer is carried above an ATM Adaptation Layer AAL-2. Therefore, a payload of an ATM cell can be comprised of data from two or more sessions, each session having been executed between different users. In addition, a chain of consecutive cells can carry data of different types from sessions between different users. A session is defined as a communication between a source and a destination (users) and is executed according to a combination of one or more protocols. Furthermore, in a 3G network, usually the user's layer is encrypted. It should be understood that the term “user's frame/packet” is used interchangeably in the herein as the term can refer to a data chunk that was created by an audio or video encoder or any other application used by the user.
A common way to satisfy the needs of users without overloading the capacity of a service provider infrastructure is by offering different types of services with varying levels of associated quality (QoS). For example, a real time communication telephone session over a cellular network may have the highest level of QoS whereas a data communication based on Internet Protocol (IP) may correspond to a lesser quality of service defined as “best effort.”
Another strategy to meet the needs of users without overloading the capacity of a network is to actively manage bandwidth. Decisions along such lines may incorporate policies of dropping certain types of communication, increasing latency of other types of communication, etc. Bandwidth management decisions are often based on the traffic contracts of network users. If a user is exceeding its traffic contract, for example, the network may either drop or delay a portion of the user's traffic. Commonly, bandwidth management decisions are made in a central network point, such as an RNC, and based on the load over a certain connection path being used by a given user.
Segments of fixed cellular networks serve as aggregation points, or points of concentration (POC), for loads that originate from various intermediate nodes with designations to be transferred on a common communication link. Therefore, there is a need for adapting bandwidth management decisions at the egress of the node closer to the communication link to consider the real load over the physical connection. If, however, the bandwidth management decision must be made at a point between the RNC and the MT, for example at the access to an ATM bearer identification of the communication type over a certain channel will be difficult because an entire user's frame or packet with its header can be encrypted and be divided into small ATM cells. More specifically, an ATM cell can be divided into small portions with each portion being associated with a different session. Furthermore, there is no control or signaling information associated with an ATM cell such that the session types carried by an ATM cell can be identified.
Taking the aforementioned into consideration, therefore, there is a need for a system and method suitable for identifying the type of communication that is transferred between two intermediate nodes over a communication link that has a plurality of different channels or sub-channels each of which carry unique, encrypted data. With accurate identification of the communication types, subsequent bandwidth management decisions can be made such that a mobile telecommunications system can have increased bandwidth utilization without jeopardizing user contracted QoS levels.